More than half of high-risk atrial fibrillation patients are not prescribed oral anticoagulants.

HealthDay News — Fewer than half of atrial fibrillation patients at highest risk for stroke are prescribed recommended anticoagulation, according to research published online in JAMA Cardiology.

Jonathan Hsu, MD, cardiologist and assistant professor of medicine at the University of California, San Diego, and colleagues tracked 429,417 outpatients seen at 144 practices in the United States between 2008 and 2012. Patients' average age was 71. Each patient's stroke risk was ranked on the basis of standardized tests, and compared against prescription patterns.

Across the whole spectrum of atrial fibrillation stroke risk, the investigators found that 44.9% of patients were prescribed an oral anticoagulant, while 25.9% were prescribed aspirin and 5.5% were offered aspirin plus a thienopyridine. Almost one-quarter (23.8%) were given no stroke-risk medication at all. In general, the team determined that the likelihood of being prescribed an oral anticoagulant rose with every 1-point increase in a patient's standardized stroke risk score. However, the odds for receiving anticoagulation prescription hit a ceiling, leaving more than half of the highest-risk patients unprotected.

"The fact that there seemed to be a plateau of oral anticoagulation prescription of those at highest risk of stroke should be a wake-up call to all of us who treat patients with atrial fibrillation," Hsu told HealthDay. Part of the problem could simply be "patient preference," he said. On the other hand, cardiologists may place too much emphasis on the risk for bleeding that anticoagulation poses. But for most patients the benefits are worth the risk, Hsu added.